iOS 生成 UUID(GUID)

iOS 生成 UUID（或者叫GUID）例子代码

NSString * gen_uuid()

{

CFUUIDRef uuid_ref = CFUUIDCreate(NULL);

CFStringRef uuid_string_ref= CFUUIDCreateString(NULL, uuid_ref);

CFRelease(uuid_ref);

NSString *uuid = [NSString stringWithString:(NSString*)uuid_string_ref];

CFRelease(uuid_string_ref);

return uuid;

}